This invention relates to electronic sewing machines of the type wherein two or more stitch forming instrumentalities may be individually actuated independent of all other stitch forming instrumentalities.
Sewing machines are known wherein the positional coordinates for successive stitch penetrations are stored in an electronic memory having addressable locations corresponding to a plurality of operator selectable patterns. Such known sewing machines include logic circuitry which is used to select and release the stitch pattern information stored in the memory in timed relation with the operation of the sewing machine. Digital information from the memory is converted to positional analog signals which control closed loop servo systems including moving coil linear or rotary actuators directly controlling the position of conventional stitch forming instrumentalities of the sewing machine to reproduce a pattern of stitches corresponding to the selected stitch information. See for example, U.S. Pat. No. 4,074,642, Feb. 21, 1978, Herr and U.S. Pat. No. 3,984,745, Oct. 5, 1976, Minalga, the teachings of which are incorporated herein by reference. Positional sensing devices provide feed back within the closed loop servos, as disclosed in U.S. Pat. No. 3,976,019, Aug. 24, 1976, Allen et al, the teachings of which are incorporated herein by reference. Typically, two or more actuators are used in these sewing machines, a unique actuator dedicated to each individually controllable stitch forming instrumentality. These actuators, however, are heavy, bulky, and expensive to manufacture. It is therefore an object of the present invention to utilize a single actuator to individually control a plurality of stitch forming instrumentalities.